A variety of approaches to optical imaging have been used for many different applications, such as for research, testing and treatment of diseases or other illnesses. For example, endoscopes and other imaging devices have been used for imaging tissue in anesthetized animals.
With the growing number of approaches to the analysis of live beings, there has been growth in technologies benefiting from such analysis as well as in the need to perform extensive analysis of the impact of such technologies. For example, imaging cellular and sub-cellular functions in live animals is desirable for many areas of biological research. Fluorescent probes have been implemented for expression in specific cell classes of genetically-engineered animals. Fluorescence microendoscopy involving one- or two-photon fluorescence excitation has been used to image biological cells in tissue, and have been implemented with relatively deep-tissue analysis. See, e.g., J. C. Jung and M. J. Schnitzer, Opt. Lett. 28, 902 (2003); see also J. C. Jung, A. D. Mehta, E. Aksay, R. Stepnoski, and M. J. Schnitzer, J. Neurophysiol. 92, 3121 (2004). These and other approaches are useful, for example, in the development of new drugs and therapeutics.
In many applications, optical imaging requires anesthetized or otherwise immobilized subjects. These requirements have presented challenges not only to the ability to obtain optical data, but to the analysis of subjects. For instance, an anesthetized or immobile state may be available under limited conditions of time and environment.
The above and other issues have presented challenges to optical analysis approaches and, in particular, to optical imaging in live beings.